Pneumatic control



March 1952 T. G. A. SILLERS PNEUMATIC CONTROL 2 SHEETS-SHEET 1 Filed Feb. 20, 1947 5mm 5m. gmm

March 4, 1952 T. G. A. SILLERS PNEUMATIC CONTROL 2 SHEETSSHEET 2 Filed Feb. 20, 1947 iv nu (9 Patented Mar. 4, 1952 2,588,329 PNEUMATIC coNrRoL Thomas G. A. Sillers, Wauwatos'a,

Wis, assignor' to Allis-Chalmers Manufacturing Company; Milwaukee, Wis., a corporation of Delaware Application February 20, 1947', serial No. 729,754

3 Claims. 1

This invention relates to a system comprising electric circuit control means which uses fluid under pressure in its operation and means for supplying fluid under pressure to the circuit control means, and the principal object of the invention is to provide new and improved systems of this type.

Another object of the invention is the provision of new and improved systems of this type in which the circuit control means is bodily movable into and out of a position in which it is adapted to control an electric circuit and coupling means is provided for connecting and disconnecting the means supplying the circuit control means with fluid under pressure to a primary source of fluid under pressure, and a more specific object is the provision of new and improved coupling means for making said connection and disconnection automatically in response to predetermined bodily movement of said circuit control means.

Another object of the invention is the provision of new and improved coupling means whereby connection and disconnection to a primary source of fluid under pressure may be made without loss of fluid from said primary source.

Another object of the invention is the provision of new and improved systems of the type hereinbefore referred to in which a supply of fluid under pressure for the circuit control means will be assured at all times in normal operation of the system regardless of bodily changes in the position of the circuit control means.

Other objects will appear as the description of the invention proceeds.

The novel features of the invention and how the objects are obtained will appear from this specification and the accompanying drawings showing several embodiments of the invention and forming part of this specification and all these novel features are intended to be pointed out in the claims.

In the drawings:

Fig. 1 is a side elevation of a circuit control apparatus embodying the invention;

Fig. 2 is a vertical section of a fluid coupling embodied in the apparatus of Fig. l,- taken on the line II-II of Fig. 3;

Fig. 3 is a rear elevation of the fluid coupling shown in Fig. 2;

Fig. 4 is a vertical section of another embodiment of a fluid coupling similar to that shown in Fig. 2.

As shown in Fig. 1, the switchgear cubicle It! comprises a three phase circuit breaker H,- one of the phases of which is visible, utilizing com-v pressed air' for its operation; the breaker H beirig shown, for purposes of more clearly disclosing the invention, electrically and mechanically disconnected from its associated electrical system, of which only the terminal contacts l2 are shown.

The particular construction and arrangement of the circuit breaker l I whereby air may be used to open and/or close the breaker and/or extinguish or assist in extinguishing the arc upon the opening of the breaker under current carrying conditions, forms no part of the present invention, and hence any desired and suitable circuit breaker may be used, utilizing air, or other gas, or any other suitable fluid medium.

Means is provided in the cubicle l0 whereby the circuit breaker H may be electrically and mechanically connected to and disconnected from the terminal contacts 12.

As shown in Fig.- 1, the circuitbreaker II is rigidly mounted in a lifting frame [3 which is vertically movable within the cubicle l0, and capable of 7 being withdrawn from the cubicle when in a lowered position, by means of casters l4 afiixed at the bottom of frame l3.

In order to raise and lower the frame I 3 within the cubicle H], the frame 13 is detachably secured to a lifting mechanism I5 operatively mounted within the cubicle In. The lifting mechanism comprises jackscrews ll depending from cubicle braces l8; the screws I! being coupled for simultaneous rotation by means of a flexible drive l9, indicated in part by dotted line. The screws I! are rota-ted manually, or by motor drive, not shown, from a power shaft 20 drivingly connected with one of the forwardly mounted screws ll through a pair of bevel gears 2|.

Elevating the frame iii-from the position shown in Figure 1 brings the relatively movable disconnect terminal contacts 23 of the breaker ll into mechanical and electrical connection with the relatively fixed electrical system terminal contacts l2 mounted in the cubicle In; the contacts' l2 being enclosed by sleeve insulators 24. When so elevated the breaker II is operatively connected with the electrical system represented by the terminal contacts I 2'. To insure electrical isolation of the breaker II from the electrical system following opening of the breaker, an auxiliary electrical disconnect switch 25 (one phase shown) is inserted in series with the breaker II and is operated independently of the operation of the breaker by any suitable means. Lowering the frame l3 separates the contacts 12 and 23 and disconnects the breaker H from the electrical system.

Mounted in the frame I3 with the breaker II to furnish a supply of compressed air to the breaker, is an air storage tank 23, which is in turn supplied with air by means of a vertical inlet fluid conduit 2'! connected therewith. Escape of compressed air through the conduit 21 from the tank 26 when the circuit breaker I I is in the lowered position, as shown in Figure l, is prevented by means of a check valve 29 mounted in the conduit 21 between the tank 25 and the open end of the conduit. The valve 29 normally remains closed so long as the air pressure within the tank 28 exceeds the air pressure on the inlet side of the valve. The conduit 21 extends above the lifting frame I3 and terminates in a coupling element 33, which has a suitable upper face.

Air for the operation of the breaker I I is piped into the cubicle II] from an external primary source of compressed air, not shown, by means of a horizontally positioned header conduit 3I mounted in the cubicle above the lifting frame I3 and it is assumed for the purposes of the following disclosure that the air pressure in the conduit 3I exceeds the air pressure in the tank 23. Coupling means is provided in the cubicle 18 for connecting the conduit 3| with the conduit 21 substantially simultaneously upon connection of the breaker I I with the electrical system terminals I2, and such means, hereinafter to be described, also includes means to prevent the escape of air from the conduit 3I when the breaker II is in the disconnected position, as shown in Figure 1.

As shown in Fig. 3, which illustrates a preferred embodiment, the coupling means comprises essentially a rigid coupling unit 32 which is mechanically and pneumatically connected with the header conduit 3 I, so that air forced into the conduit 3I under pressure from the external source of compressed air will be introduced into the coupling 32. The coupling 32 is so mounted in the cubicle II) as to have a receiver portion 33 positioned vertically over the movable coupling element 33. The particular construction of the coupling means 32 which provides for the operative interaction of the coupling .element 33 with the receiver 33, whereby air is conveyed without loss from the conduit 3I to the conduit 2'! simultaneously upon connection of the breaker to the electrical system, forms part of the present invention and will hereinafter be described in detail.

As shown in Fig. 2, the coupling 32 comprises an L-shaped housing 35 having a chambered vertical portion 33 and a chambered horizontal portion 31 which discharges into the receiver 33. As shown in Fig. 3 the vertical portion 36 of the housing 35 has formed integrally with its upper structure a conventional conduit T 38 adapted to receive in sealed connection opposite end portions of the conduit 3I. The joints formed by the intersection of the ends of the conduit portions 3I with the T 38 are respectively sealed against air leakage by conventional packing glands 39 associated with the T.

The housing 35 has its interior divided into an upper chamber M and a lower chamber ll-which are interconnected by a passageway 43 constructed in an inner transverse wall 44 of the housing. Air entering the chamber 4| from the conduit 3| is admitted to the lower chamber 42 through the passageway 43. From the chamber 42 the air is discharged through a suitable opening, as will appear, in the housing 35 into the receiver 33. However, the air flow through the coupling 'the aperture 43 33 is subject to interruption at two points in the housing; namely, at the passageway 43, and at the wall opening into the receiver 33. To ac complish control of the passage of air through the coupling 32 the coupling is provided with two valves, hereinafter to be described; one manually operated, the other automatically operated. As shown in Fig. 2, the portion 31 of the housing 35 has two longitudinally spaced apertures 45 and 43 located in its underwall; the aperture 45 being adapted to receive automatic valve elements associated with the receiver 33 and aperture 46 being adapted to receive valve elements associated with a manually operated valve 41, as will appear.

The valve comprises the usual stem guide housing 39 bolted to the coupling housing 35 over in the housing underwall. Threaded in the conventional manner into the guide housing 49 is a valve stem 58 which carries on its inner end a valve disk 5|. The disk 5I engages a valve seat 52 formed in the wall 44 about the passageway 43. Included with the disk 5I is the conventional washer 53 mounted thereon for purposes of maintaining a positive airtight seal between the disk 5| and the valve seat 52 when the valve 41 is closed A sealing ring 54, interposed between the guide housing 49 and the coupling housing 35, insures an air-tight seal at the joint between the two housings and further provides a cushion for the valve disk 5I when the valve disk is in a full retracted position. By operating valve 4! the passageway 43 may be either opened or closed to control the passage of air within the coupling 32 from the chamber ll to the chamber 42.

The release of air from the chamber 42 of the housing 35 is regulated by an automatic valve 56 which controls the flow of air through the aperture 35 in the housings underwall into the receiver 33. The receiver 33 which dominates the aperture 45 and forms an integral part of the housing 35 comprises a stationary cylindrical tube 5? and actuating means comprising a relatively axially-movable cylindrical tube 58. The stationary tube 51 extends downward a limited distance from the housing 35 so as to both shield, and provide a suitable housing for the tube 58 and the other elements associated with the receiver 33, as will appear. As heretofore noted, the longitudinal axis of the tube 51 is coaxial with the longitudinal axis of the coupling element 38, a necessary condition for the mating of the coupling element 3!! with the tube 58 of coupling 32 upon elevation of the breaker II;

which mating operation will be described hereinafter in detail.

The stationary tube 51 is fastened to the housing 35 of the coupling 32 in the following manner. The upper end of the tube 51 is securely fastened in any suitable way to the lower radial surface of a ring 59. In turn, the upper radial surface of the ring 59 is suitably secured to the outside surface of the lower wall of the housing 35, the

-joints forming an air-tight seal between the receiver 33 and the housing 35. An inside portion of the ring 59 is bent downward to form a lip '30 which provides the necessary shoulder surface to retain one end of a flexible air-tight bellows 6| attached air-tight thereto. The other end of the bellows BI is secured air-tight to a shoulder 62 integral with the bottom end of the tube 58.

The tube 58 extends for a limited distance into the chamber 42 of the housing 35. The portion of the tube 58 which is located in the chamber 42 has, in part, a reduced diameter bore 64 in which a relatively movable valve stem 65 is loosely mounted for limited axial movement. The stem 65 which lies wholly within the chamber 42 carries at and fastened to its inner end the valve 58 which is cup-shaped and which extends around and over the end portion of the tube 51 to close the aperture 45 in the housing 35 by engagement with a valve seat 56. The reverse end of the stem 65 comprises an integrally formed shoulder 8? of substantially greater diameter than the bore 54 of the tube 58. The stem 65 is thus constrained and limited in its axial movement, relative to the tube 58, by the shoulder 61 on the one hand and the valve 56 on the other. Located in the wall of end portion, but lying below the stem shoulder 81, are a number of circumferentially spaced circular ports 88, which, when the tube is in the extreme lowered position, as shown in Fig. 2, are below the valve seat 55. Upward movement of the tube 58 opens the valve 56 b direct mechanical contact Of the end of the tube 58 with the underside of the valve 58 and at the same time uncovers the ports 88 of the tube within the chamber 52 whereby air may freely flow from the chamber 42 through the ports 88 into the tube 58. Lowering the tube 53 back into the position shown in Fig. 2 closes the valve 56 by action of the end of the tube 58 on the stem shoulder 61; substantially covers the ports 88; and cuts off the flow of air from the coupling 82 into the tube 58.

Among the elements of the receiver 33, the portion of the shoulder 82 of the tube 58 lying below the bellows 6! is externally threaded to receive a threaded nut 18. The nut it! is keyed to the tube 58, so as to fixedly secure it to the tube, by means of a key 7 l; a portion of the nut '58 extending below the bottom end of the tube 58. Threaded into the lower end of the nut 18 is an externally threaded nut 72, having an inside diameter substantially greater than the diameter of the bore of the tube 58. An annular seal 13 having a diameter equal to the diameter of the shoulder 62 of the tube 58, is interposed between the nut I2 and the bottom of the tube 58. Screws I4 cooperating with the nut l8 bear against the nut 12 to retain it firmly in position.

Valve biasing means is interposed between the top of the nut 18 and the bottom of the ring 59 and comprises a coil spring 15.

The elements of the receiver structure 33, hereinbefore described, coact to normally maintain the valve 58 in a closed position and are adapted upon upward movement of the tube 58 to permit air flow from the chamber 42 of the coupling 32 into the receiver 33.

For all positions of the tubes 58 in the receiver 33, the bellows 6| form an air-tight resilient connection between the tube 58 and the housing 35. In this way air which leaks through the clearance between the tube 58 and the housing 35 is trapped in the cylindrical space between the tube 58 and the bellows 6 I.

The operation of the coupling 32 whereby the conduit 3| is coupled to the conduit 21 upon elevation of the breaker l I from the electrically disconnect position shown in Fig. 1 to the electrically connect position hereinbefore described, is as follows:

As the lifting frame I3 is elevated by the action of the jackscrews I! in a manner hereinbefore described, the coupling element 38 forming the .upper. end of the conduit 2'! comes into contact the tube 58 at its upper with the bottom of the movable tube 58 of the coupling receiver 33, as shown in Fig. 2. Specifically the face of the coupling element 38 contacts and intimately engages the face of the seal 13 of the tube 58, thereby forming a substantially air-tight connection between the element 30 and the tube 58.

As the frame 13 continues to be elevated, the tube 58 is forced upward under the action of the coupling element 38, until the tube comes into contact with the valve 58, whereupon further movement upward of the tube opens the valve, at the same time exposing the tube ports 68 to compressed air in the chamber 42. For any position of the tube 58 the coil spring i5 is constantly exerting a downward force on the tube, which force is in opposition to the force exerted upward by the coupling element 38. The two forces assist in preserving a substantially air-tight connection between the coupling element 38 and the tube 58 while the breaker H is in an elevated position. As the breaker I l is elevated, the coupling between the element 38 and the tube 58 is made before the valve 56 opens. In this way no air is admitted to the coupling between the conduits 3| and 21 until the two conduits are positively coupled through the coupling 32. Air is then conveyed by means of the coupling 32 from the conduit 3| to the conduit 21 without loss of air at the coupling.

The coupling heretofore described between the conduits 3| and 21 upon connection of the breaker H to the electrical system i2 is disestablished in the following manner:

The breaker H is lowered from its uppermost connected position, which downward movement lowers the coupling element 38 and allows the tube 58 in the receiver 33 to move downward under the action of gravity and the spring 15. The valve 56 closes under the action of gravity, which is in some cases assisted by the air pressure in chamber 42. When the tube 58 reaches its lowermost position, as shown in Fig. 2, the valve 55 is prevented from reopening by the stem which acts to restrain upward movement of the valve and forces it against the seat 88. As the breaker ll continues to be lowered the coupling element 38 separates from the tube 58 whereupon the check valve 29 acts to prevent escape of compressed air from the tank 28 through the conduit 21.

The manually operated valve 4': permits a permanent cut off of the air supply at the coupling 32 should replacement of any of the elements of the receiver 38 become necessary for any reason.

The embodiment shown in Fig. comprises a coupling I1 corresponding to the coupling but in this embodiment the manually operated valve is eliminated and air from an external source, not shown, enters a 'i" 78 where it flows directly into a chamber 73 formed in a coupling housing 85: the housing 88 being bolted to the underside of the T 18 so as to form a continuous integral structure with the T. The housing 85 is cupshaped and has a base flange 8! from which a flexible bellows 82 depends and is fastened airtight thereto. The lower end portion of the bellows 82 is securely fastened air-tight to a movable tube 83; the connection being made to a shoulder 84 forming an integral part of the lower end portion of the tube. The tube 33 extends upwardly through the bellows 82 and into a vertical passageway 85 formed in the base of the housing 80. The passageway 85 is closed at its upper end by a check valve 85 movably the side walls of the chamber 19.

mounted in the housing 80 and biased for closure by a coil spring 81; the spring 81 being interposed between the base flange of the T 18 and the upper face of the check valve 86. Depending from the base flange of the T i8 is a suitable guide 88 for maintaining the spring 81 in coaxial relation with Similarly the valve 86 has integrally formed on its upper face an upwardly extending guide 89 which coacts with the lower end portion of the spring 81 to maintain the valve 86 in coaxial alignment with the upper opening of the passageway 85. An annular seal 90, inserted in an annular recess in the bottom of the chamber 79 forms a valve seat for the valve 86.

The tube 83 has located in its upper end portion a number of circumferentially spaced circular ports 9| opening at right angles to the axis of the tube. When the tube 83 is elevated the check valve 86 is opened and the ports 9| of the tube are exposed to the compressed air in the chamber 19 whereby air passes from the T 18 into the tube 83. At the base of the tube 83 an annular seal 92 is inserted.

The operation of the coupling ll is quite similar to the operation of the coupling 32 hereinbefore described. The coupling element 30 attached to the frame I3 is brought into contact with bottom of the movable tube 83 upon elevation of the frame. Upon contact, the face of the element 3i} intimately engages the face of the seal 92 of the tube, thereby forming a substantially air-tight connection between the element 30 and the tube 83. As the frame l3 continues to be raised the tube 83 continues upward under the action of the coupling element 3% until the tube contacts the valve 86, whereupon further upward movement of the tube, opens the valve. Air from the chamber 19 is then admitted, as heretofore described, into the tube 83 through the ports SI of the tube. For all positions of the tube 83 the coil spring 81 is continually exerting a downward force on the tube, which is counteracted by an upwardly directed force exerted through the coupling element 313. The two forces assist in preserving a substantially air-tight connection between the coupling element 33 and the tube 83 while the frame 13 is in an elevated position. As the frame [3 is elevated the coupling between the element 30 and the tube 83 is made before the valve 86 is opened. This sequence of first coupling conduit 3| to the T l9 and then opening the valve 86 insures that no air is admitted to the coupling between the T 18 and the conduit 2; until the two are positively coupled. Air is then free to flow through the coupling ii to the conduit 21 without loss of air at the coupling.

The coupling between the T 18 and the coupling element 30 is disestablished in a reverse sequence to that described above.

Lowering the coupling element 3:! lowers the tube 83 and closes the valve 8%. Lowering the coupling element 30 still further causes the coupling element to separate from the tube 83, thereby breaking the coupling between the T !8 and the conduit 21. As the coupling is broken the check valve 29 as hereinbefore described acts to prevent escape of compressed air from the tank 26 through the conduit 21.

The tank 26 which furnishes air to actuate the circuit breaker H is adequately supplied with compressed air for all normal operations of the breaker regardless of the position of the breaker in the cubicle l0. It is important to have an ade- 8 quate supply of compressed air for operating the breaker II at the instant the breaker is being electrically connected to the electrical system 12, as when the frame [3 is elevated. If at that instant any ground or fault should exist on the load side of the electrical system [2 the breaker ll must be prepared to open the circuit immediately upon connection to prevent the build up of excessive and damaging short circuit currents on the system. I

From the foregoing it will be apparent to those skilled in the art that the illustrated embodiments of the invention provide a new and improved pneumatic control for circuit breakers and accordingly accomplishes the objects of the invention.

On the other hand, it will also be obvious to those skilled in the art that the illustrated embodiments of the invention may be variously changed and modified, or features thereof, singly or collectively, embodied in other combinations than those illustrated, without departing from the spirit of the invention, or sacrificing all of the advantages thereof, and that accordingly the disclosure herein is illustrative only and the invention is not limited thereto.

It is claimed and desired to secure by Letters Patent:

1. Circuit control apparatus comprising a,

switch having fluid-operated contact separating means for breaking an electric circuit, said apparatus comprising a circuit containing fluid under pressure, means for simultaneously affording connection of said switch with said electric and fluid pressure circuits comprising first electric terminals connected with said electric circuit, first conduit means connected with said fluid pressure circuit, second electric terminals connected with said switch and engageable with said first electric terminals for connecting said switch to said electric circuit, second conduit means connected to said contact separating means and engageable with said first conduit means for supplying said fluid-operated contact separating means with fluid under pressure from said fluid pressure circuit, common actuating means for effecting simultaneous movement of said second electric terminals and said second conduit means for engagement with said first electric terminals and said first conduit means respectively whereby said switch is substantially simultaneously connected to said electric and fluid pressure circuits, and means for containing fluid under pressure interposed between said second conduit means and said fluid-operated contact separating meansfor maintaining the pressure of the operating fluid within predetermined limits during operation of said contact separating means.

2. Circuit control apparatus comprising a switch having fluid-operated contact separating means for breaking an electric circuit, said apparatus comprising a circuit containing fluid under pressure, means for simultaneously affording connection of said switch with said electric and fluid pressure circuits comprising first electric terminals connected with said electric circuit, first conduit means connected with said fluid pressure circuit, second electric terminals connected with said switch and engageable with said first electric terminals for connecting said switch to said electric circuit, second conduit means connected to said contact separating means and engageable with said first conduit means for supplying said fiuid-operated contact separating means with fluid under pressure from said fluid pressure circuit, common actuating means for effecting simultaneous movement of said second electric terminals and said second conduit means for engagement with said first electric terminals and said first conduit means respectively whereby said switch is substantially simultaneously connected to said electric and fluid pressure circuits, means for containing fluid under pressure interposed between said second conduit means and said fluid-operated contact separating means for maintaining the pressure of the operating fluid within predetermined limits during operation of said contact separating means, and valve means operable in response to completion of the connecting movement of said second conduit means for opening the connection between said fluid pressure circuit and said fluid containing means through said first and second conduit means, and operable in response to disconnecting movement of said second conduit means for preventing the escape of fluid from said fluid pressure circuit through said first conduit means.

3. In a separable resilient fluid coupling, the combination of a first movable coupling member having a passage for the flow of fluid therethrough, a second coupling member comprising a housing having a wall portion provided with an opening for the flow of fluid therethrough, valve means mounted in said housing operable to open and close said opening to valve said fluid, tube means mounted on said housing for conducting fluid passing through said opening, said tube means being movable relative to said housing and having an apertured shoulder for fluid tight sealing engagement with said first coupling member 10 after a predetermined movement of said first coupling member toward said wall portion, means for forming a fluid tight resilient seal between said tube and said housing comprising resilient bellows means having one end in fluid tight connection with said wall portion adjacent said opening and having the other end in fluid tight connection with one end of said tube means, and actuating means including the other end of said tube means and lost motion means, said actuating means connected by said lost motion means with said valve means and movable through said bellows means and said opening to actuate said valve means and uncover said opening in response to continued movement of said first coupling member toward said wall portion after said sealing engagement between said shoulder and said first coupling member.

THOMAS G. A. SILLERS.

REFEREN CES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

